Magnetic levitation apparatus and method

DETAILED DESCRIPTION What I claim is: 1.
An apparatus for levitating objects in a magnetic field, comprising: at least one electromagnet positioned in alignment with an object, said electromagnet having a core centrally disposed within, said core having one end positioned adjacent an outer surface of said electromagnet; at least one electrical power coupling for connecting said electromagnet to an electrical power source; a first magnetic field sensor disposed adjacent said one core end, and a second magnetic field sensor mounted adjacent an opposite core end and in an opposite orientation to said first sensor with respect to magnetic fields generated by said electromagnet, said sensors capable of providing output signals proportional to a sensed magnetic field level; at least one magnet secured to the object to be levitated in alignment with said core and having a field strength sufficient to move said object relative to said core; summing means for summing said sensor output signals; reference means for generating a reference voltage signal; comparator mean connected to said summing means and reference means for comparing respective voltages generated by said summing and reference means; a field strength controller connected in series with said power source for adjusting electrical power delivered to said electromagnet in response to differences detected by said comparator means.
2.
The levitation apparatus of claim 1 wherein said core has a high field saturation value and a low retention value.
3.
The levitation apparatus of claim 1 wherein: said electrical power coupling comprises two conductive lines, one of said lines being connected to said electromagnet and the other being connected to said field strength controller; and said field strength controller comprises a switching transistor disposed in series with said electromagnet.
4.
The levitation apparatus of claim 3 wherein said transistor is a power Field Effect Transistor.
5.
The levitation apparatus of claim 3 further comprising gating means coupled between said comparison means and said power transistor for applying a turn on voltage to a control input of said transistor in response to said comparison means output signal